查看更多>>摘要：? 2021 Elsevier B.V.Furoic acid, an important biobased furan chemical, was synthesized from available, inexpensive and renewable bulrushes (Phragmites communis) via chemoenzymatic route in aqueous media containing DES (deep eutectic solvent) as an additive. Organic carboxylic acid as HBD (hydrogen-bond-donor) was used to prepare ChCl-based DES for transforming bulrushes to furfural. By studying the relationship between pKa value of different organic acids in DESs and furfural yield, ChCl-based DES with citric acid (pKa = 3.13) as HBD could obtain higher furfural yield. ChCl:Citric acid (20.0 vol% dose) yielded furfural (75.5 mM) at 47.64% yield from AS-bulrush (NaOH-soaked bulrush) at 180 °C in 30 min. Characteristics of untreated and pretreated bulrushes were captured with XRD (X-ray diffraction), FT-IR (Fourier transform infrare spectra), and SEM (scanning electron microscope). AS-bulrush-valorized furfural was sequentially biotransformed into furoic acid with HMFOMUT (Recombinant E. coli HMFOMUT) whole-cells at 30 °C in ChCl:Citric acid–H2O (pH 7.0). The yield of furoic acid reached 42.51% after 56 h. This study developed an environmentally friendly strategy for chemoenzymatic cascade catalysis of lignocellulosic biomass into furoic acid via tandem chemocatalysis and biocatalysis in ChCl:Citric acid–H2O. It was feasible to produce value-added furan-based chemicals from the renewable sources.
查看更多>>摘要：? 2022 Elsevier B.V.Economical and eco-friendly lignocellulose pretreatment technology, and enzymatic sugar production are an urgent demands for fermentation into valuable platform chemicals. In this work, we explored that pretreatment of corn cobs and corn stalks based on scCO2 at pressure (35–45 MPa), temperature (40 ℃?70 ℃) and moisture content (0 wt% ? 85 wt%), time (1–24 h), and in term of pretreatment effect to investigate the enzymatic hydrolysis yield. The pressurized biphasic system of CO2-H2O generates carbonic acid in situ to promote the hydrolysis of biomass, and the drastic release of enclosed static scCO2 creates irreversible structural fragmentation for the two raw materials, as supported by various characterization techniques. Additionally, comparing the divergences in sugar yield and pretreatment mechanism between the two raw materials was due to the dominant tissue structure. Whilst trade-off high CO2 pressure and mild pretreatment temperature could achieve high enzyme digestibility compared to the untreated biomass.’
查看更多>>摘要：? 2022 Elsevier B.V.Botanical natural bioactive ingredients are difficult to purify due to their complicated composition and structure, and are usually utilized in the form of phytocomplex, which refers to a mixture of multiple bioactive ingredients. Using biocompatible solvents as delivery solvents is a simple, versatile, and scalable method to improve the solubility of phytocomplex. In this work, the extract of Ginkgo biloba leaves (EGb) was chosen as the model of the phytocomplex to systematically investigate the potential of natural deep eutectic solvents (NADESs) as solubilizers. After initial screening, the solubilities of EGb in different NADESs were 29–1500 folds higher than those in water. Several solvatochromic parameters of NADESs were employed to tentatively study the solvation between bioactive compounds and NADESs. The high solubility of EGb in NADESs could be interpreted by the hydrogen bond interactions. Additionally, further investigation on the stability and bioactivity of EGb dissolved in NADESs helped to validate the feasibility of using NADESs as solubilizers. The results suggested that not only the stability but also the bioactivity of EGb kept at high levels after dissolving in NADESs. The findings of this study showed the bright application prospect of NADESs as solubilizers, which offers a new avenue for improving the solubility of insoluble phytocomplex.
查看更多>>摘要：? 2022 Elsevier B.V.Essential oils from Lavandula angustifolia Mill. and Lavandula x intermedia Emeric x Loisel composed of concentrated terpene mixtures, and are highly produced due to their economic value. In the Mediterranean area, the production is threatened by the increasing frequency and intensity of drought events, leading to the loss of crops. Thus, we aimed to evaluate the response to water stress and the tolerance of the main French cultivated varieties of L. angustifolia and L. x intermedia during flowering period, based on the response of their primary metabolic traits (e.g. growth, photosynthesis, stomatal conductance) and specialized metabolic traits (terpene storage and emissions related to the plant defense system). Two treatments were applied: a control where plants received 300 mL every day (≈75% of substrate field capacity) and a stress where plants received 100 mL every two days (≈25% of substrate field capacity). Our results showed that both species featured a drought-tolerant strategy to cope with water stress with a more competitive strategy in L. angustifolia. Water deficit modified the amounts of stored terpenes in both species which could be economically harmful for the sector related to essential oil production. Moreover, some compounds such as bornyl acetate were highlighted as potential defense compounds. The study also highlighted that the varieties ‘Rapido’ (L. angustifolia), arecent variety developed in France, and ‘Sumian’ (L. x intermedia), could be the best candidates to cultivate under intense drought.
查看更多>>摘要：? 2022 The AuthorsIn analogue to the biorefinery concept, the separation process of lignocellulosic biomass is the most critical step to obtain its main components, namely cellulose, hemicelluloses and lignin. Moreover, the applied fractionation approach has a decisive impact on the characteristics and subsequent valorization strategies of the distinguished fractions. This review presents the state of art of novel biomass fractionation processes that are recently developed and focusing on autohydrolysis, organosolv fractionation, ionic liquid and deep eutectic solvent (DES) treatment. Moreover, the facing challenges, perspectives and future development direction in the field of fractionation of lignocellulosic biomass are discussed. The purpose of this review is to provide inspiration and guidance for fractionating biomass with environmentally friendly and efficient pathways, thus to push forward their further industrialization based on the integrated biorefinery concept.
查看更多>>摘要：? 2022 Elsevier B.V.Green polymer is made from epoxidized natural rubber (ENR) latex (natural polymer plant), N-vinylcaprolactam (NVCL), and poly (vinyl alcohol) (PVA). Firstly, NVCL was grafted onto the ENR using potassium persulfate as an initiator and its chemical structure was confirmed using ATR-FTIR and 1H NMR. The graft copolymer occurs at amorphous (non-crystalline) region confirmed by XRD. The sharp peak XRD patterns of the ENR-graft-NVCL were found at 24.82, 30.63, 31.18, 37.16, 39.62 and 43.73°, referred to the reflection of (0 0 4), (1 0 1), (1 0 3), (1 1 0), (1 1 2) and (2 0 1), respectively. XRD pattern of the ENR was observed at 2θ = 19.5°, which is amorphous portion. It was then blended with PVA to reduce the swelling ratio in the toluene medium, the moisture content and moisture absorption of the ENR-graft-NVCL/PVA blend, reduced as a function of NVCL (200%, 3% and 7%, respectively) because of its chemical interactions. Moreover, the ENR-graft-NVCL swelled 150% or about 8 times based on the pristine ENR in water medium. The lower critical solution temperature of the ENR-graft-NVCL/PVA blend was observed around 37 °C. The highest tensile strength (around 14 MPa) was observed with NVCL at 1.5 phr. The ENR-graft-NVCL showed the highest thermal stability. A sustained release profile of curcumin from this matrix was found and the release percentage of the loaded curcumin sample at 40 °C and 72 h was much lower than the release percentage of the sample at 25 °C. The biodegradation of ENR-graft-NVCL/PVA blends (25–45%) degraded in natural soils.
Francisco A.B.F.D.P.Lorevice M.V.Claro P.I.C.Gouveia R.F....
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查看更多>>摘要：? 2022 Elsevier B.V.Interest in biodegradable polymers has been increasing exponentially due to the global environmental concerns about inappropriate disposal of plastic materials. Considering this issue, poly (butylene adipate-co-terephthalate) (PBAT) is a good candidate to be applied to films, since it presents desirable, promising processability and thermal-mechanical properties and lower water solubility compared with other biopolymers. However, PBAT exhibits inferior mechanical properties compared with polyolefins. To overcome this, acetylated cellulose nanocrystals (CNCs-Ac) were systematically investigated by incorporating different weight ratios to PBAT-based films produced via a solvent casting/heat pressing approach. This process combines a well dispersed hydrophobic filler with additional temperature and pressing, ensuring improvement in yield strength (30%) and Young's modulus (90%), as well as an outstanding benefit in flexibility (> 650%), compared with neat PBAT film. This work provided a novel route to prepare PBAT bionanocomposites, showing greater potential for biodegradable packaging, which can be an alternative to conventional polymers.
查看更多>>摘要：? 2021Dissolving pulps are technically produced by prehydrolysis kraft, one-stage or two-stage acid sulfite pulping. Like other pulping methods, the delignification process is incomplete and bleaching is required for complete lignin removal. Here, we explored the molecular aspects of lignin recalcitrance during the pulping, in order to gain insights that could inform future pulping efforts. For this purpose, we adopted a protocol for the controlled fractionation of pulp into soluble fractions that could be analyzed by spectroscopic methods including size exclusion chromatography (SEC) and 2D NMR methods. In addition, lignosulfonates (i.e. technical lignin) was analysed as a reference to gain insights on the structural basis for dissolution. Overall, the results identify a sequence of reactions responsible for the dissolution of lignin. In the first stage, the sulfonation of lignin begins and occurs at the α-carbon of β-O-4 and β-5 sub-structures. In the second stage the cleavage of lignin carbohydrate bonds (LCC) of benzyl ether, gamma ester and phenylglycosides types, all of which were detected in the residual lignin of the earlier phases, occurs and enhances lignin dissolution. Finally, condensation reactions of benzylic cations with activated positions on aromatic ring were detected in lignosulfonates. This suggest that a competing reaction mode to the sulfonation at C-α position in lignin was occurring at prolonged pulping conditions, here considered to be unproductive.
查看更多>>摘要：? 2022In the present study, sodium lignosulfonate (SLS) was used to enhance the interfacial adhesion between the natural rubber latex and wool fabric. The coarse wool woven fabric was treated with various concentrations of SLS. After drying, the fabric was coated with natural rubber latex. The influence of SLS on the physico-mechanical properties of the composites was investigated. The SEM images showed that the SLS acted as a cementing material in between the wool fabric and the rubber latex. In comparison with the control composite sample, the SLS treatment causes up to a 32% increase in the areal density by enhancing the interaction between the wool fiber and latex. The SLS treatment at low concentrations significantly improved elongation of the composites in comparison with untreated wool composite, however, the water diffusion of the composites samples got considerably reduced after SLS treatment. After UV aging, 50% SLS treated sample showed better retention of tensile strength. Since the developed composite is flexible, it can be used for the development of bags, acoustics panels, and doormats.
查看更多>>摘要：? 2022 Elsevier B.V.Lignin is an abundant, renewable natural resource that shows UV resistance and whose amphiphilicity can be modified, which means that it could potentially encapsulate photo-sensitive agrichemicals. However, current technical lignins, e.g., alkaline lignin (AL), tend to form large aggregates, which severely limits its encapsulation performance. In this study, three cationic surfactants were selected for hydrophobic modification of AL, and to produce AL microspheres (AL-MPs) encapsulating abscisic acid (ABA). The surfactants tested were dodecyl tetramethyl ammonium bromide DTAB (single C12 chain), dimethyl behenyl ammonium bromide DDAB (two C12 chains) and cetylpyridinium chloride CPC (single C16 chain). The particle sizes, zeta-potentials, and encapsulation efficiencies of the AL-MPs were modified by changing the type of the surfactant and the weight percentage (wt%) of AL. The range of particle sizes, zeta potentials and encapsulation efficiencies were 232–1226 nm, –56.1–18.7 mV, and 62–78%, respectively. Fourier transform infrared spectroscopy (FTIR) was used to characterize the MPs. The photolysis protection and release of ABA from ABA-loaded MPs (e.g., ABA@AL-DDAB) were studied and a release kinetics model was built to probe the release behaviour. The effects of ABA@AL-MPs on the salt tolerance of rice seedlings under salinity stress were studied, and the mechanism is discussed. ABA@AL-MPs effectively protected the seedlings from growth inhibition by salinity stress. ABA@AL-DDAB was the most effective formulation, outperforming ABA@AL-CTAB and even the no-salt control. DDAB is less cytotoxic than CTAB and has the potential, when combine with lignin to encapsulate ABA and other agrichemicals to produce formulations with photolysis resistance and sustained-release properties.
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Elsevier